If you've been training for any extended period of time, you've probably experienced it. You go in for a session and whatever the lift is, let's say squats, feels pretty bad. No worries though, just a bad session. These things happen. But then your next session they don't feel well either. You still stay optimistic. But then the next week comes around and more of the same. Now, before each squat session, you're thinking about how you don't want to squat. You're dreading squats. When you start getting to your heavier warm-up sets, when they don't feel quite right, your first thought is "oh great, here we go again". You struggle and try to fight it, but with each set you sink deeper and deeper, getting more and more frustrated. You're caught in quicksand.
There is certainly a psychological side to lifting and, in this case, you're experiencing a bit of a self-fulfilling prophecy. A self-fulfilling prophecy is a prediction that causes itself to be true due to the behavior of the person who made the prediction. In this case, after a few bad squat sessions, you have started to go into training with the expectation that the squats are going to go poorly. This isn't to say that you are going to actively squat with bad technique or purposely squat badly, but other actions you take (or don't take) may have an influence on your performance.
Research on self-fulfilling prophecies is somewhat limited and difficult to conduct, and even more rare when it comes to exercise. However, we can take a bit of research and use that to explain how your beliefs going poorly may end up contributing to actions that lead to them feeling subpar. Wurm et al. (2013) performed a longitudinal study over 6 months, examining 309 individuals ages 65 and older who had major illnesses, to see if negative self-perceptions of aging led to self-fulfilling prophecies. The researchers found that in the case of a serious health event, this often led to the self-perception of the subjects that aging leads to physical losses. This negative self-perception led to less use of self-regulation activities that can promote a healthy lifestyle. The participants' perception was that losses with old age are inevitable, which led to them not using behaviors that may well have improved their health or made them feel better.
Obviously, the behaviors in the aforementioned study would not guarantee better health, there is simply a relationship between those self-regulation activities and improved health, and we know that correlation does not equal causation. However, we can still apply this to our squat scenario. As our frustrations increased with squats, were there any other changes in behavior that may have started to contribute to your squats feeling subpar. Let's run down a checklist of questions to ask and behaviors to look at to see if we're guilty of creating our own self-fulfilling prophecy:
Are you doing something new with training or have you made a change to technique recently that you are still working on? If so, this can take a bit to feel "normal". Just be patient
How long has it been since you've deloaded? Maybe you're due for one and need to take one and let yourself rest up a bit
Have you had any additional stressors happen that happened to coincide with squats starting to feel less than stellar?
Look at your sleep, nutrition, and hydration on the days before and days of squats since they started feeling rough. Have you changed anything? Are you being more lackadaisical in any of these areas because "squats are going to feel like crap anyway"?
Are you rushing through your warmups or not being quite as precise as you usually would be because you want to get squats over with?
This list is certainly not all encompassing, but it is a good starting point to look and see if we just need to tweak training slightly or be patient, if other stressors have contributed, or if we have participated (or not participated) in behaviors that may have contributed to us performing at a level we aren't happy with. There are other questions we can ask ourselves too, but this is a start.
If you look at that list and there have been no changes and there doesn't seem to be a reason for why one or more of your lifts doesn't feel great, that's okay too! Understand that sometimes we just get in a funk and things don't feel great. It's important to stay consistent and keep going in there and getting some practice in, even when a movement doesn't feel particularly awesome. If you do your own programming, this is a time to re-evaluate and ensure that volumes aren't higher than they need to be and if some tweaks can be made to get you back on the right track. If you have a coach, communication with them, as always, is critical. They can't make any changes unless they know you're struggling. Talk with them, and they should make some modifications to get you headed on the right path.
In the end, it comes down to patience and having a short memory. Putting bad sessions in the past and leaving them there, and treating your next session as a clean slate. Bad sessions, bad weeks, even sometimes a bad month can happen. Make sure you're controlling all the variables you can control, stay as positive as possible, stay consistent, and you'll avoid the quicksand.
Reference
Wurm, S., Warner, L. M., Ziegelmann, J. P., Wolff, J. K., & Schüz, B. (2013). How do negative self-perceptions of aging become a self-fulfilling prophecy?.Psychology and Aging,28(4), 1088.